This page contains various debugger settings. There should normally be no reason to change these. Note that if you are running more than one debugging session at the time you must change the port number so that they don't come into conflict with each other.
The GDB proxy is a service providing the communication between the target device and the debugger (GDB). You may not want to start an instance in case it is already running, maybe even on another computer. Use these settings to set up the instance used for the debugging session.